Surface Segregation of NbAl₃ Alloys by Boron Doping

First-principles calculations have been performed to investigate the segregation energies and electronic structures of boron element in the NbAl₃ surfaces. The calculated results show that the boron can spontaneously segregate from bulk to surface, which is good for the high-temperature oxidation resistance. The bonding interactions between boron and its neighboring Nb atoms are enhanced, indicating that the boron stability in NbAl₃ surfaces becomes stronger when boron atoms move from interior to surface. Moreover, the electronic structures before and after boron substitutions have been analyzed, which favor the possible migration path.